QHY8L Cooling Issues....HELP!


#1

Hello all, I am having a real panic here with cooling my QHY8L with SG.

I have the ASCOM driver installed which reads as follows in my Win 7 64 control panel:

“QHYCCD QHY8L ASCOM Camera Driver 3.3.0”

I have used with the Auto control cooling system in EZCap and all seems to work fine

In SG Pro though, I connect to the camera, plug in the power supply to the 8L’s power
supply box as that is the correct procedure.

I have SG set to not turn on cooling on connection as I prefer to control that directly myself
at this point as i’m very new to SG. With the 8L displaying a temp of 21.4c I do the following:

  1. Set the ‘Set Temperature To’ box to 21c

  2. Set ‘Change Over’ to 5m

  3. Turn Cooler to ON

  4. Hit the ‘SET’ button

Power shoots straight up to 30% bringing my +21c temp aggressively fast down to
8.5c while the power slowly drops to 1% over about 1 min or so and stays at 1%

So my question is, as I set the ‘Set Temp To’ box actually slightly lower than the
temp shown by the cameras temp sensor, why did SG turn power on immediately
to 30% power It was a bit scary for sure ???

Thanks
Paul


#2

Paul,

A few things…

  • SGPro cannot control your TECs power. This is a decision left to the ASCOM (and native driver). We ask it to move to a particular temperature and it figures out how to do this.
  • You will want to talk to your driver’s author as to why this happens. I just tested functionality to ensure it wasn’t broken. When you click set, SGPro asks your camera to cool to some small temperature increment (since you only asked to cool down 0.4 degrees). The rest is up to your driver.
  • The driver may respond better to a situation where you are not trying to cool only 0.4 degrees. Why don’t you try to cool down to 5 degrees if you are testing… see how that works.

#3

Thanks Ken,

That makes sense, ill have a chat with the ASCOM boys to see what else I can find out there.

Incidentally, I was not actually trying to cool it by 0.4c, more just setting the temp to as close
as possible to the temp reported by the 8L at that time so it wouldn’t actually cool or warm but
stay at the temp it was at when turning the cooler to ON.

On reflection, just setting Cooling to ‘ON’ and not actually clicking the SET button with any temp
should just maintain the current temp the 8L is reporting but the cooling system is then active &
ready to respond, ignoring my 30% power on situation, would that be a reasonable assessment
of clicking cooling to ‘ON’ ?

Cheers
Paul


www.mainsequencesoftware.com